Gniezno

City · c. 1025 CE · in Europe

Capital of Kingdom of Poland (1025–1385).

Suzdal (1024 CE): Capital of Principality of Rostov-Suzdal (1125–1240), Principality of Vladimir-Suzdal (1294–1389).
Niebla (c. 1023 CE): Capital of Taifa of Niebla (1023–1053).
Seville (c. 1028 CE): Capital of Taifa of Seville (1028–1091).
Faro (c. 1018 CE): Capital of Taifa of Santa Maria do Algarve (1018–1051).
Béjaïa (c. 1018 CE): Capital of Hammadid Dynasty (1018–1151).
Olomouc (1017 CE): Capital of Margraviate of Moravia (1385–1414).
Almería (c. 1015 CE): Capital of Taifa of Almería (1015–1147).
Murcia (c. 1015 CE): Capital of Taifa of Murcia (1015–1249).
Huelva (c. 1015 CE): Capital of Taifa of Saltés and Huelva (1015–1051).
Granada (c. 1015 CE): Capital of Taifa of Granada (1015–1090), Emirate of Granada (1241–1491).

Around the same time and place

Christianization of Kievan Rus' (988 CE): Vladimir the Great adopted Orthodox Christianity from Byzantium and had the people of Kyiv baptised in the Dnieper.
William the Conqueror (c. 1028 CE – 1087 CE): Duke of Normandy who conquered England in 1066 and became its first Norman king.
Battle of Hastings (1066 CE): William, Duke of Normandy, defeated and killed King Harold II, beginning the Norman conquest of England.
Trier (16 BCE – 1618 CE): Capital of Electorate of Trier (1333–1618).
Varangians to the Greeks (c. 800–1100 CE): Scandinavian traders and warriors travelled from the Baltic up the Neva and Volkhov past Novgorod, portaged to the Dnieper and sailed down past Kiev to the Black Sea and Constantinople.
Stephen I of Hungary (c. 975 CE – 1038 CE): First king of Hungary, crowned in 1000 or 1001, who converted his people to Christianity; venerated as Saint Stephen.
Stockholm (c. 980 CE): Capital of Kingdom of Sweden (980–today), Kalmar Union (1436–1523), Swedish Empire (1612–1721), and 1 more.
Bruges (c. 990 CE): Capital of County of Flanders (990–1384).